The present invention relates to an ignition device of an engine.
In an ignition device of a gasoline combustion engine, a spark plug that is provided for each cylinder is connected to an igniter, and the spark plug is energized by turning on and off the primary electric current to a primary winding of the igniter thereby to generate a high voltage in a secondary winding of the ignition coil, with the result that air-fuel mixture is ignited. Japanese Patent Application Publication No. H09-170545 discloses an igniter having an abnormality detection circuit that measures electric current for detecting malfunction of the igniter.
In the case where an igniter having an abnormality detecting circuit cannot be used because of the mounting restriction in the gasoline engine, malfunction or abnormality of the spark plug that is not directly electrically connected may not detected. In addition, the use of the abnormality detection circuit increases the cost of the igniter.
The present invention, which has been made in light of the above-described problems, is directed to providing an ignition device of an engine that can detect the abnormality using an igniter without an abnormality detecting circuit.